Stacking apparatus and stacking method

ABSTRACT

A stacking apparatus that stacks a first substrate and a second substrate includes: a plurality of holding members that hold the first substrate, wherein the plurality of holding members correct positional misalignment of the first substrate relative to the second substrate by preset amounts of correction, and the plurality of holding members include holding members having the amounts of correction that are different from each other. The stacking apparatus may further include a carrying unit that carries a holding member that is selected from among the plurality of holding members and holds the first substrate from a position where the holding member is housed to a position where the first substrate is held.

BACKGROUND 1. Technical Field

The contents of the following Japanese and International patentapplications are incorporated herein by reference:

NO. 2016-120021 filed on Jun. 16, 2016, and

NO. PCT/JP2017/021874 filed on Jun. 13, 2017.

The present invention relates to a stacking apparatus and a stackingmethod.

2. Related Art

A stacked semiconductor device is manufactured by stacking substrates(please see Patent Literature 1, for example).

[Patent Literature 1] Japanese Patent Application Publication No.2013-258377

There is a need for improvement in precision of alignment of substratesto be stacked.

A first aspect of the present invention provides a stacking apparatusthat stacks a first substrate and a second substrate, the stackingapparatus including: a plurality of holding members that hold the firstsubstrate, wherein the plurality of holding members correct positionalmisalignment of the first substrate relative to the second substrate bypreset amounts of correction, and the plurality of holding membersinclude holding members having the amounts of correction that aredifferent from each other.

A second aspect of the present invention provides a stacking method ofstacking a first substrate and a second substrate, the stacking methodincluding: preparing a plurality of holding members that holds the firstsubstrate and corrects positional misalignment of the first substraterelative to the second substrate by preset amounts of correction, theplurality of holding members including holding members to correct thefirst substrate by amounts of correction that are different from eachother, and causing any of the plurality of holding members to hold thefirst substrate based on information about the first substrate and thesecond substrate.

The summary clause does not necessarily describe all necessary featuresof the embodiments of the present invention. The present invention mayalso be a sub-combination of the features described above.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a stacking apparatus 100.

FIG. 2 is a flowchart showing a stacking procedure.

FIG. 3 is a schematic view for explaining measurement of a substrate 210in a prealigner 500.

FIG. 4 is a schematic cross sectional view of a substrate holder 221.

FIG. 5 is a schematic view of a holder stocker 400.

FIG. 6 is a schematic cross sectional view of a substrate holder 223holding a substrate 213.

FIG. 7 is a schematic view of the holder stocker 400.

FIG. 8 is a schematic cross sectional view of a stacking unit 300.

FIG. 9 is a schematic plan view of a substrate 210.

FIG. 10 is a schematic cross sectional view of the stacking unit 300.

FIG. 11 is a schematic cross sectional view of the stacking unit 300.

FIG. 12 is a schematic cross sectional view of the stacking unit 300.

FIG. 13 is a schematic view showing how substrates 211, 213 appear inthe stacking unit 300.

FIG. 14 is a schematic cross sectional view of the stacking unit 300.

FIG. 15 is a schematic view showing how the substrates 211, 213 appearin the stacking unit 300.

FIG. 16 is a schematic view showing how the substrates 211, 213 appearin the stacking unit 300.

FIG. 17 is a schematic view of the holder stocker 400.

FIG. 18 is a schematic view of a holder stocker 401.

FIG. 19 is a schematic view of a substrate cassette 120.

FIG. 20 is a schematic view of a stacking apparatus 101.

FIG. 21 is a schematic view of a stage apparatus 340.

FIG. 22 is a schematic view of the stage apparatus 340.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, some embodiments of the present invention will bedescribed. The embodiment(s) do(es) not limit the invention according tothe claims, and all the combinations of the features described in theembodiment(s) are not necessarily essential to means provided by aspectsof the invention.

FIG. 1 is a schematic plan view of a stacking apparatus 100. Thestacking apparatus 100 is an apparatus that stacks one substrate 210 anda different substrate 210 to form a stacked body 230. The stackingapparatus 100 includes: a housing 110; substrate cassettes 120, 130 anda control unit 150 that are disposed outside the housing 110; and acarrying unit 140, a stacking unit 300, a holder stocker 400 and aprealigner 500 that are disposed inside the housing 110.

One of the substrate cassettes, the substrate cassette 120, houses aplurality of substrates 210 to be stacked. The different one of thesubstrate cassettes, the substrate cassette 130, houses a plurality ofstacked bodies 230 formed by stacking substrates 210. A plurality ofsubstrates 210 can be carried into the stacking apparatus 100collectively by using the substrate cassette 120. In addition, aplurality of stacked bodies 230 can be carried out of the stackingapparatus 100 collectively by using the substrate cassette 130.

The carrying unit 140 carries, inside the stacking apparatus 100, any ofa substrate 210, a substrate holder 220, a substrate holder 220 holdinga substrate 210 and a stacked body 230 formed by stacking substrates210. A plurality of substrate holders 220 are housed in the holderstocker 400.

Substrate holders 220 are exemplary holding members, and are highlyrigid disk-like members having dimensions larger than substrates 210.Each of the substrate holders 220 has the function of suctionallyattracting substrates which is realized by an electrostatic chuck, avacuum chuck or the like, and individually holds substrates 210 insidethe stacking apparatus 100. Thereby, substrate holders 220 are carriedtogether with fragile substrates 210 by the carrying unit 140 whileprotecting the substrates 210. Holding members to hold substrates 210are not limited to the substrate holders 220, but stages on whichsubstrates 210 are placed in the stacking unit 300 of the stackingapparatus 100 may also be holding members.

The prealigner 500 detects the center of a substrate 210, positions thecenter of the substrate 210 to match the center of a substrate holder220, and causes the substrate holder 220 to hold the substrate 210 inthat state. In addition, the prealigner 500 aligns the relativepositions and directions of a substrate 210 and a substrate holder 220,and reduces the load of a positional alignment process in the stackingunit 300 mentioned below. Furthermore, the prealigner 500 is used alsoin separating a stacked body 230 carried out of the stacking unit 300from a substrate holder 220.

The control unit 150 performs overall control of individual units of thestacking apparatus 100 such that they cooperate with each other. Inaddition, upon receiving a user instruction from the outside, thecontrol unit 150 sets manufacturing conditions to be applied inmanufacturing stacked bodies 230. Furthermore, the control unit 150 alsohas a user interface that displays the operation state of the stackingapparatus 100 toward the outside.

Still furthermore, the control unit 150 has a holder selecting unit 151and a substrate selecting unit 152. The holder selecting unit 151 is anexemplary holding member selecting unit, and selects substrate holders220 satisfying a predetermined condition among a plurality of substrateholders 220 housed in the holder stocker 400. The predeterminedcondition is that the substrate holders 220 will be able to holdsubstrates 210 with positional misalignment between the substrates 210that occurs in a formed stacked body 230 not exceeding a threshold whenthe substrates 210 are stacked in the stacking apparatus 100.

Here, a plurality of substrate holders 220 housed in the holder stocker400 each has a holding surface to hold a substrate 210, and theindividual holding surfaces have states that are different from eachother. The states are at least one of: the magnitudes of the degrees ofconvexness of the holding surfaces of the plurality of substrate holders220; the magnitudes of the curvatures of the holding surfaces; thelevels of the temperatures of the holding surfaces; the degrees of thesurface roughness of the holding surfaces; and the strengths of theholding forces of the holding surfaces.

In this manner, a plurality of substrate holders 220 having holdingsurfaces in states that are different from each other are prepared, anda substrate holder 220 to be used when a substrate 210 is stacked isselected appropriately; thereby, positional misalignment betweensubstrates 210 in a stacked body 230 can be suppressed or removed asmentioned below.

The substrate selecting unit 152 selects a substrate 210 suited for asubstrate holder 220 from a plurality of substrates 210 housed in thesubstrate cassette 120. For a substrate 210, the holder selecting unit151 selects, from a plurality of substrate holders 220 housed in theholder stocker 400, a substrate holder 220 to hold the substrate 210. Incontrast, for one substrate holder 220, the substrate selecting unit 152selects a substrate 210 that allows suppression or removal of positionalmisalignment between the substrate 210 and a different substrate 210 ina stacked body 230 by the former substrate 210 being held by thesubstrate holder 220. Selection operation of these holder selecting unit151 and substrate selecting unit 152 is mentioned below.

The stacking unit 300 has a pair of stages that each hold a substrate210 and face each other, and after the substrates 210 held on the stagesare aligned with each other, brings them into contact with each otherand stacks them to thereby form a stacked body 230. Substrates 210 arecarried into the stacking unit 300 while being kept held by substrateholders 220, and are stacked in the stacking unit 300.

A stacked body 230 formed in the thus-structured stacking apparatus 100is finally separated from substrate holders 220 carried out of thestacking apparatus 100. Therefore, the substrate holders 220 separatedfrom substrates 210 or the stacked body 230 stay inside the stackingapparatus 100 and used repeatedly. Therefore, the substrate holders 220can be considered as constituting part of the stacking apparatus 100.

Substrates 210 to be stacked in the stacking apparatus 100 may besubstrates 210 on which devices, circuits, terminals or the like areformed or may otherwise be unprocessed silicon wafers, compoundsemiconductor wafers, glass substrates or the like. In addition, acombination of substrates 210 to be stacked may consist of a circuitsubstrate and an unprocessed substrate or may consist of unprocessedsubstrates. Furthermore, substrates 210 to be stacked may themselves bestacked bodies 230 already formed by stacking a plurality of substrates.

FIG. 2 is a flowchart showing a procedure performed in the stackingapparatus 100 to stack substrates 210 and fabricate a stacked body 230.FIG. 2 is referred to at many points in the following explanations.

The control unit 150 of the stacking apparatus 100 first measures thestate of a substrate 210 carried into the stacking apparatus 100 fromthe substrate cassette 120 using the carrying unit 140 (Step S101).Here, the state of the substrate 210 means the extent of a difference inthe shape of the substrate 210 from a predetermined shape. In addition,the extent of the difference for example means the amount of thedifference of the substrate 210 from a predetermined imaginary flatshape.

FIG. 3 is a schematic view showing an example of measurement of asubstrate 210 using part of the prealigner 500. The prealigner 500 has arotation drive unit 510, an edge detecting unit 520 and a distancemeasuring unit 530.

The rotation drive unit 510 rotates a substrate 210 mounted thereonwhile supporting portions near the center of the substrate 210 againstgravity. The edge detecting unit 520 continuously detects positions ofexternal circumferential end portions of the rotating substrate 210.Thereby, the prealigner 500 detects an eccentricity of the substrate 210relative to the rotation center and detects the geometric center of theindividual substrate 210. In addition, the prealigner 500 detects anotch or the like provided to the substrate 210 and detects also theorientation of the substrate 210.

When the substrate 210 is to be held by the substrate holder 220, theprealigner 500 aligns the detected central position and orientation ofthe substrate 210 with the center and orientation of the substrateholder 220 so that they match each other. Thereby, when the substrate210 is aligned with a different substrate 210, extremely largepositional misalignment is prevented, and the load of a highly precisealignment process can be suppressed.

The prealigner 500 further measures deformation of the substrate 210using the distance measuring unit 530. The distance measuring unit 530detects a distance to the bottom surface (in the figure) of the rotatingsubstrate 210 in a direction parallel with the axis of rotation.Thereby, it is possible to detect deformation of the substrate 210 inthe thickness direction successively in the circumferential directionbased on fluctuation in the detected distance. Furthermore, by causingthe distance measuring unit 530 to scan the substrate 210 in the radialdirection, it is possible to measure the state about deformation of theentire substrate 210. Such a state about deformation of the entiresubstrate 210 is one type of shape-related information of a substrate210. The shape-related information of the substrate 210 is one type ofinformation about two substrates 210 to be bonded together.

A substrate 210 detected to be deformed to an extent greater than apredetermined range at this step may be determined as not being suitedfor stacking. The substrate 210 determined as not being suited forstacking may be carried to a predetermined position, for example, aparticular housing position in the substrate cassette 130, and excludedfrom to-be-stacked objects.

Determination of excluding a substrate 210 from to-be-stacked objectsmay be made for example based on a fact that an amount of deformation ofa substrate 210 exceeds a predetermined range. Here, being exceeding apredetermined range for example means that a substrate 210 is sodeformed that a suctional attraction force of a substrate holder 220,which is a holding member, is not sufficient for the substrate 210 to beclosely adhered to a holding surface of the substrate holder 220.

In addition, being exceeding a predetermined range for example meansthat an amount of deformation of a substrate 210 having become ato-be-measured object exceeds the limit of amounts of correction incorrection mentioned below. Furthermore, being exceeding a predeterminedrange means for example that if a combination of a substrate 210 havingbecome a to-be-measured object and a substrate 210 to be stacked onto itis already determined, positional misalignment due to a differencebetween amounts of deformation of the two substrate 210 has reached amagnitude that cannot be removed in correction mentioned below. Anamount of correction is an amount of deformation that is caused to atleast either one of two substrates 210 to be joined with each other suchthat positional misalignment between the two substrates 210 becomesequal to or smaller than a threshold.

One example of the threshold is a misalignment amount that allows atleast partial contact between connection portions individually providedto the substrates 210. If a misalignment amount has become equal to orlarger than this threshold, the connection portions do not contact eachother, appropriate electrical connection cannot be obtained, or apredetermined joining strength cannot be obtained between the joiningportions.

About a substrate 210 that is not excluded from to-be-stacked objects atthis step, the holder selecting unit 151 of the control unit 150determines whether or not correction is necessary according toindividual measurement results, and if correction is necessary, furthercalculates an amount of correction. Furthermore, the holder selectingunit 151 selects, from a plurality of substrate holders 220, a substrateholder 220 to hold the substrate 210 such that positional misalignmentbetween the substrate 210 and a different substrate 210 generated to astacked body 230 formed by the substrates 210 does not exceed thethreshold (Step S102).

The prealigner 500 causes the selected substrate holder 220 to hold thesubstrate 210 (Step S103). If positional misalignment is corrected bydeforming one of two substrates 210 to be stacked such that the onesubstrate 210 matches the different substrate 210, the differentsubstrate 210 does not require deformation for correction of positionalmisalignment.

FIG. 4 is a schematic cross sectional view of a substrate holder 221 tohold one substrate 211 of two substrates 210 to be stacked in thestacking apparatus 100. The substrate holder 221 has a flat holdingsurface 225 and the function of suctionally attracting and holding thesubstrate 211 which is realized by an electrostatic chuck, vacuum chuckor the like.

The one substrate 211 of the two substrates 210 is, as mentioned below,released from holding by the substrate holder 221 at a step of beingstacked onto the different substrate 213. In the present example, theone substrate 211 is held by a substrate holder 221 having a flatholding surface 225. Therefore, the holder selecting unit 151 selectsthe substrate holder 221 having the flat holding surface 225 asillustrated in the figure, as a substrate holder 221 to hold thesubstrate 211. If a substrate 211 is mentioned in the followingexplanation, it refers to one that is held by one substrate holder 221among two substrates 210 to be stacked.

FIG. 5 is a schematic view of the holder stocker 400 housing substrateholders 221. The holder stocker 400 has a plurality of housing units,and can house the plurality of substrate holders 221. In the exampleillustrated in the figure, three among a large number of housing unitseach house one substrate holder 221.

The three substrate holders 221 illustrated in the figure have the samespecification. The holder selecting unit 151 determines which one amongthe substrate holders 221 to use such that their wear becomes uniform,and so on. Different substrate holders 223 housed in the holder stocker400 that are indicated by dotted lines in the figure are explained nextwith reference to FIG. 6.

FIG. 6 is a schematic cross sectional view of a different substrateholder 223 holding a different substrate 213. A holding surface 225 ofthe substrate holder 223 protrudes at its middle, and there is adifference in height B generated between the middle of the holdingsurface 225 and its edge portions. This difference in height B is anexemplary degree of convexness of the substrate holder 223.

In addition, the substrate holder 223 has the function of suctionallyattracting and holding the substrate 211 which is realized by anelectrostatic chuck, vacuum chuck or the like. Therefore, the substrate213 held by the substrate holder 223 has a shape with a protrudingmiddle conforming to the shape of the holding surface 225. If asubstrate 213 is mentioned in the following explanation, it refers toone that is held by a different substrate holder 223 among substrates210 to be stacked.

If the substrate 213 is deformed as illustrated in the figure, thesubstrate 213 is extended above an alternate long and short dash line Aindicating the middle of the substrate 213 in the thickness direction.Therefore, on the top surface (in the figure) of the substrate 213, themagnification of a circuit or the like formed on the surface of thesubstrate 213 relative to its designed dimension increases. On the otherhand, on the lower side (in the figure) relative to the alternate longand short dash line A, the substrate 213 contracts, and themagnification of the bottom surface (in the figure) relative to itsdesigned dimension decreases.

The magnifications mentioned here is one type of distortion which isdeformation generated to the substrate 213. Distortion generated to thesubstrate 213 includes: components that have constant tendency over theentire substrate 213 such as magnification components that causedistortion in radial directions from the center of the substrate ororthogonal components; and non-linear components other than them.Orthogonal component distortion is for example distortion generated inopposite directions: in two regions that are divided by a line segmentpassing through the center of a substrate; and along a line segmentpassing through the center. The components of magnifications includethose related to isotropic magnifications that generate the same amountof deformation in the X-direction and Y-direction, and those related toanisotropic magnifications that generate different amounts ofdeformation in the X-direction and Y-direction, and the anisotropicmagnification components are included in the non-linear components.

These types of distortion are caused by: stress generated in processesof forming alignment marks 218 or circuit regions 216 in the substrate210; anisotropy due to crystalline orientation of the substrate 210;constantly repetitive changes in rigidity due to the arrangement or thelike of scribe lines 212, circuit regions 216 or the like; or the like.In addition, even if distortion is not generated to the substrate 210before being bonded, in the course of bonding, the substrate 210 isdeformed and distorted occasionally at the boundary between contactregions which are regions already contacting and non-contact regionswhich are regions yet to contact.

Magnifications to be corrected in the present example are isotropicmagnifications, and are one of indices that are among the states ofsubstrates measured at Step S101 and indicate extent of differences froma predetermined shape. In addition, magnifications are values (ppm) thatrepresent differences in size from the design value of the substrate 210in proportions of dimensions in the plane direction. Distortionincluding such magnifications is one type of shape-related informationof the substrate 210.

In this manner, the substrate holder 223 having the difference in heightB at the holding surface 225 can correct the substrate 213 to change itsmagnification by deforming the suctionally attracted substrate 213.Therefore, for example, if there is a magnification difference remainingas positional misalignment between the substrate 213 and the substrate211 at the step at which alignment of the two substrates 211, 213 iscompleted or after they are stacked, correction to reduce amagnification difference between the substrates 211, 213 is performed bystacking the substrate 213 with its magnification being kept changed bythe substrate holder 223, and positional misalignment between thesubstrates 211, 213 due to the magnification difference can becorrected.

Here, positional misalignment between the stacked substrates 211, 213 ispositional misalignment between their corresponding alignment marks andtheir corresponding connection portions, and includes positionalmisalignment due to a difference between amounts of distortion resultingfrom deformation of the substrates 211, 213 such as warping.

In addition, positional misalignment also include positionalmisalignment due to deformation of the substrate 211 generated in thecourse of stacking the substrates 211, 213. That is, in the course ofstacking the substrates 211, 213, they are joined by releasing holdingof the one substrate 211 toward the different held substrate 213.Therefore, deformation generated in the course of joining to thereleased substrate 211 has influence also after being joined, and thiscauses positional misalignment.

The amount of correction of magnification correction of the substrate213 by the substrate holder 223 changes according to the shape of thesurface on which the substrate holder 223 holds the substrate 213. Inthe present example, it changes according to the degree of convexnessrelative to a flat plane. The degree of convexness represents adifference between the highest position and lowest position of theholding surface on which the substrate holder 220 holds the substrate210 when the substrate holder 220 is placed horizontally, and, in thepresent example, is indicated by the difference in height B of at middleportion of the holding surface 225 from a plane of the holding surface225 including its edge portions.

The above-mentioned curvature is the curvature of an arc of the holdingsurface 225 when the substrate holder 223 is seen along a longitudinalsection passing through the center of the substrate holder 223. Even ifdegrees of convexness are the same, curvatures of holding surfaces 225of substrate holders 223 are different if the sizes of the holdingsurfaces 225 are different. If substrates 213 are held by such substrateholders 223, amounts of correction of the substrates 213 are differentfrom each other even if degrees of convexness are the same. Therefore,specifications of substrate holders 223 are stored to include:combinations of degrees of convexness and diameters; and amounts ofcorrection, in combination with each other. Conversely, if it is knownthat the diameters of a plurality of substrate holders 223 are the same,an amount of correction of a substrate 213 held by each of thesubstrates holders 223 can be grasped based on the degree of convexnessof the substrate holder 223.

FIG. 7 is a schematic view of the holder stocker 400 housing substrateholders 223. A plurality of substrate holders 223 having holdingsurfaces 225 with degrees of convexness that are different from eachother are housed in the holder stocker 400. In the example illustratedin the figure, individually different states of the plurality ofsubstrate holders 223 are magnitudes of the degrees of convexness oftheir holding surfaces 225.

In the example illustrated in the figure, the range of the amounts ofcorrection that can be made with the entire plurality of substrateholders 223 is −10 ppm to +10 ppm. This range is a range of correctionthat can be made for a remaining amount of misalignment when, forexample, both a substrate holder 223 and another correcting mechanismare used, and an amount of misalignment that cannot be corrected by thecorrecting mechanism is corrected by the substrate holder 223. Here, thecorrecting mechanism for example is a mechanism that: includes aplurality of actuators that can extend or contract, a plurality ofpneumatic units or the like that are arranged on a plane; and deforms asubstrate supported by the plurality of actuators or plurality ofpneumatic units into a desired shape by driving them. A differencebetween an amount of correction set to each of the plurality ofsubstrate holders 223 and an amount of correction that should actuallybe made may be calculated by the holder selecting unit 151, and in thestate where a substrate which is a to-be-corrected object is held by asubstrate holder 223, the substrate and substrate holder 223 may bedeformed by the correcting mechanism to thereby compensate for thedifference with the correcting mechanism. The relationship betweendegrees of convexness or substrate holders 223 and amounts of correctionis preset and stored, and an amount of correction of a substrate holder223 with a degree of convexness of 1 μm is 0.08 ppm, for example. Inaddition, the range of pitch of amounts of correction of the pluralityof substrate holders 223 is 0.1 to 1 ppm, and the pitch may be constantor differ among the plurality of substrate holders 223.

According to the state of a substrate 211, that is, a result ofmeasurement at the prealigner 500, the holder selecting unit 151 selectsa substrate holder 223 having a holding surface 225 with a degree ofconvexness that can correct a substrate 213 to be in a state that adifference between a magnification of the one substrate 211 estimatedbased on a preliminarily stored relationship between warp amounts andmagnifications, and a magnification of the different substrate 213estimated from a measurement result of the substrate 213, that is, anamount of positional misalignment between the two substrates 211, 213,does not exceed a predetermined threshold.

The magnification of the substrate 213 can also be known from measuredpositions of alignment marks of the substrate 213. If a magnification isestimated based on a result of measurement about the shape of thesubstrate 213, both changes in a magnification due to deformation of thesubstrate 211 generated in the course of stacking and a difference inmagnifications due to deformation generated to the two substrates 211,213 individually in the course of manufacturing before stacking the twosubstrates 211, 213 may be estimated, and an amount of correction may bedetermined based on both of them.

A warp amount of a substrate 213 is one of indices indicating an extentof a difference from a predetermined shape among states of a substratemeasured at Step S101, and particularly is a value indicating an amountof deformation in the direction of the thickness of a substrate 210. Thewarp amount mentioned here is an amount of deformation in the directionof the thickness of a substrate minus a component of an amount ofdeformation generated due to an external force like gravity to act onthe substrate 210, and is distinguished from an amount of bendingincluding also an amount of deformation due to an external force.

If physical properties of the substrate 210 such as a bending strengthare grasped preliminarily, it is possible to predict or estimate a warpamount of the substrate 210 from an amount of bending of the substrate210. A component of an amount of deformation due to an external force toact on the substrate 210 can be detected by measuring an amount ofdeformation of an unwarped substrate 210 by the same method and underthe same condition as those for a warped substrate 210. Such a warpamount and amount of bending are one type of shape-related informationof the substrate 210.

In addition, if a plurality of substrate holders 223 having holdingsurfaces 225 with different magnitudes of curvature as their states areused, the holder selecting unit 151 may select, from the plurality ofsubstrate holders 223, a substrate holder 223 having a curvaturecorresponding to an amount of correction that is to be made betweensubstrates 211, 213 to be stacked. Amounts of correction and curvaturesor substrate holders 223 are preliminarily stored in association witheach other. An amount of correction that should be made by a substrateholder 223 is determined according to a combination of two substrates211, 213 to be stacked, and for example is calculated from amagnification difference between the two substrates 211, 213. In thepresent example, the holder selecting unit 151 functions as acalculating unit to calculate an amount of correction.

The holder selecting unit 151 may select a substrate holder 223 usingnot a result of measurement by the prealigner 500 but anotherdetermination criterion.

For example, if there is a measurement value about the state of asubstrate 213 carried into the stacking unit 300 that is alreadymeasured by a processing apparatus outside the stacking unit 300, forexample, an exposure apparatus, a polishing apparatus, a film-formingapparatus or the like, the holder selecting unit 151 may acquire themeasurement value and use it as a selection criterion. The measurementvalue used here for example includes a magnification value, an amount ofdeformation (a warp amount, an amount of bending or the like), an amountof correction that needs to be made between two substrates 211, 213, andthe like, which is shape-related information of each of the twosubstrates 211, 213.

In addition, if there are characteristics that should be corrected,appearing qualitatively based on contents of a process upstream of thestacking unit 300 like a film-formation process, a manufacturing deviceused in this upstream process, the structure of a substrate 213 and thelike, they may be uses as preconditions of a criterion in selecting asubstrate holder 223. For example, warp amounts of or amounts of bendingof substrates are comparable, and amounts of correction that should bemade are comparable if those substrates are substrates belonging to thesame lot, substrates manufactured in the same process, or substratesthat share a processing history such as a processing apparatus used in aprocess, information about the lot, process, processing history or thelike may be received from a processing apparatus, and a substrate holder223 may be selected for replacement based on the received information.In this case, substrate holders 223 to be used may be replacedlot-by-lot or processing history-by-processing history.

Furthermore, as a process separate from a stacking process, the state ofa substrate 213 may be measured using measurement devices other than theprealigner 500 provided to the stacking unit 300, for example,microscopes 324, 334 in the stacking unit 300 or the like. Thereby,other than a state that appears to an appearance of a substrate 213 asdeformation or the like, the distribution of residual stress in thesubstrate 213 or the like can be a to-be-corrected characteristic.

Although in the above-mentioned example, warping of a substrate 210 ismeasured using the prealigner 500, it may be measured by a differentmethod. For example, deformation of a substrate 213 in the planedirection can be measured by causing any predetermined substrate holder223 to hold the substrate 213 and executing enhanced global alignment atthe stacking unit 300 using alignment marks 218 provided to thesubstrate 213 as index marks. Based on a result of this measurement, atleast one of the amount of positional misalignment between twosubstrates 211, 213 and the amount of correction therefor may bepredicted, and a substrate holder 223 corresponding to those amounts maybe selected by the holder selecting unit 151, or amounts of deformationwhich are measurement results and substrate holders 223 may beassociated with each other in advance or amounts of deformation andamounts of correction may be associated with each other in advance, anda substrate holder 223 may be selected by the holder selecting unit 151according to an amount of deformation. The amount of positionalmisalignment between two substrates 211, 213 and the amount ofcorrection therefor are each one type of information about twosubstrates 211, 213.

In addition, if the amount of positional misalignment between alignmentmarks 218 on substrates 211, 213 that are already stacked and joined orthe like is measured, and a different substrate 211 or 213 having acommon specification is stacked, the holder selecting unit 151 mayselect a substrate holder 223 to use based on the measurement result.Furthermore, in measurement of joined substrates 211, 213, a warp amountor amount of bending may be measured, instead of a positionalmisalignment amount. In this case, the holder selecting unit 151 mayselect a substrate holder 223 based on a preliminarily storedrelationship between warp amounts and misalignment amounts.

Furthermore, when selecting a substrate holder 223, the holder selectingunit 151 may acquire information about factors to cause fluctuation ofmagnifications generated to substrates 211, 213 such as temperaturechanges during joining processes or changes in conditions of activationof substrates 211, 213, and based on these types of information, mayreview a result of selection based on a measured positional misalignmentamount, warp amount or bending amount.

In this manner, the stacking apparatus 100 includes a plurality ofsubstrate holders 223 that have degrees of convexness that are differentfrom each other and can provide amounts of correction of substrates 213that are different from each other. Each of the plurality of substrateholders 223 corrects the states of substrates 213 in amounts ofcorrection that are different from each other. That is, the plurality ofsubstrate holders 223 causes deformation of substrates 213 by amountsthat are different from each other when they are held by the pluralityof substrate holders 223, and make amounts of changes in shapes of thesubstrates 213 before and after the holding different from each other.

Referring to FIG. 2 again, substrate holders 221, 213 individuallyholding substrates 211, 213 to be placed one on another at Step S102 aresequentially carried into the stacking unit 300 (Step S104).

FIG. 8 shows how it appears after the substrate holder 221, 213 holdingthe substrates 211, 213 are carried into the stacking unit 300, togetherwith the structure of the stacking unit 300. The stacking unit 300 inthe stacking apparatus 100 includes a frame body 310, a fixation stage322 and a moving stage 332.

The frame body 310 has a base plate 312 and a top plate 316 that areparallel with a floor surface 301, and a plurality of supports 314 thatare vertical to the floor plate.

The fixation stage 322 fixed to the bottom surface (in the figure) ofthe top plate 316 facing downward has the hold function which isrealized by a vacuum chuck, an electrostatic chuck or the like. Asillustrated in the figure, the substrate 211 is held by the fixationstage 322 together with the substrate holder 221 having a flat holdingsurface 225.

A microscope 324 and an activating apparatus 326 are fixed to the bottomsurface of the top plate 316. The microscope 324 enables observation ofthe top surface of the substrate 213 held by the moving stage 332arranged to face the fixation stage 322. The activating apparatus 326generates plasma to activate the top surface of the substrate 213 heldby the moving stage 332.

The moving stage 332 is mounted on a Y-direction drive unit 333 thatmoves in the direction indicated by the arrow Y in the figure. TheY-direction drive unit 333 is placed on an X-direction drive unit 331disposed on the base plate 312. The X-direction drive unit 331 moves inthe direction indicated by the arrow X in the figure, in parallel withthe base plate 312. Thereby, the moving stage 332 can move in theX-Y-direction two-dimensionally. A substrate 213 held by the substrateholder 223 is held by the moving stage 332 illustrated in the figure. Ashas been explained with reference to FIG. 6, the substrate holder 223has a curved holding surface 225, and the substrate 213 also is held ina state where it is corrected along the holding surface 225.

In addition, the moving stage 332 rises and lowers relative to theY-direction drive unit 333 due to a Z-direction drive unit 335 thatrises and lowers in the direction indicated by the arrow Z.

The amount of movement of the moving stage 332 realized by theX-direction drive unit 331, Y-direction drive unit 333 and Z-directiondrive unit 335 is minutely measured using an interferometer or the like.In addition, the X-direction drive unit 331 and Y-direction drive unit333 may each be configured to have two stages consisting of a coarsemovement unit and a fine movement unit. Thereby, both highly precisealignment and high throughput can be achieved to make it possible tojoin the substrate 211 mounted on the moving stage 332, moving thesubstrate 211 fast without lowering control precision.

On the Y-direction drive unit 333, a microscope 334 and an activatingapparatus 336 are individually further mounted laterally next to themoving stage 332. The microscope 334 enables observation of thedownward-facing bottom surface of the substrate 213 held by the fixationstage 322. The activating apparatus 336 generates plasma to activate thebottom surface of the substrate 213 held by the fixation stage 322.

The stacking unit 300 may further include a rotation drive unit thatrotates the moving stage 332 about a rotation axis vertical to the baseplate 312 and an oscillation drive unit that oscillates the moving stage332. Thereby, the precision of aligning the substrates 211, 213 can beimproved by rotating the substrate 211 held by the moving stage 332, aswell as by making the moving stage 332 parallel with the fixation stage322.

The control unit 150 preliminarily calibrates the microscopes 324, 334by adjusting the foci of the microscope 324, 334 to match each other,causing them to observe a common index mark, and so on. Thereby, therelative positions of the pair of microscopes 324, 334 in the stackingunit 300 are measured. Next, referring to FIG. 2 again, alignment marksformed in each of the substrates 211, 213 are detected in the stackingunit 300 (Step S105).

FIG. 9 is a schematic plan view of a substrate 210 (211, 213) to beplaced on a different substrate in the stacking apparatus 100. Thesubstrate 210 has: a notch 214; and a plurality of circuit regions 216and a plurality of alignment marks 218.

The circuit regions 216 are disposed on a surface of the substrate 210constantly repetitively in the plane direction of the substrate 210.Each of the circuit regions 216 is provided with a semiconductor device,wire, protection film or the like formed by a photolithography techniqueor the like. Also in the circuit regions 216 are disposed structuresincluding connection portions such as pads or bumps to serve asconnection terminals if the substrate 210 is to be electricallyconnected to a different substrate 210, a lead frame or the like.

The alignment marks 218 are an exemplary structure formed on a surfaceof the substrate 210, and are disposed to overlap scribe lines 212disposed between the circuit regions 216. The alignment marks 218 areutilized as index marks in aligning this substrate 210 with a differentsubstrate 210 which is a to-be-stacked object.

FIG. 10 is a figure for explaining operation of the stacking unit 300 atStep S105. At Step S105, the control unit 150 operates the X-directiondrive unit 331 and Y-direction drive unit 333 to detect, using themicroscopes 324, 334, alignment marks 218 provided to the individualsubstrates 211, 213.

In this manner, by detecting the positions of the alignment marks 218 ofthe substrates 211, 213 using the microscopes 324, 334 whose relativepositions are known, the control unit 150 can calculate the relativepositions of the substrates 211, 213 (Step S106). That is, in thestacking unit 300, an amount of movement of the moving stage 332 iscalculated such that the detected positions of the alignment marks 218match or corresponding circuit regions 216 overlap one on another.

FIG. 2 is referred to again. Next, the control unit 150 activates jointsurfaces of the substrates 211, 213 to be stacked (Step S107).

FIG. 11 is a figure for explaining operation of the stacking unit 300 atStep S107. At Step S107, the control unit 150 chemically activates ajoint surface of each among the pair of substrates 211, 213 while at thesame time maintaining the relative positions of the pair of substrates211, 213.

The control unit 150 first resets the position of the moving stage 332to its initial position, then moves horizontally, and causes theactivating apparatuses 326, 336 to scan surfaces of the substrates 211,213 with plasma generated thereby. Thereby, the individual surfaces ofthe substrates 211, 213 are purified and become chemically highlyactive. Therefore, the substrates 211, 213 autonomously suctionallyattract each other and join with each other by being in contact with orapproaching each other.

The activating apparatuses 326, 336 radiate plasma P in directions awayfrom the individual microscopes 324, 334. Thereby, it is possible toprevent the microscopes 324, 334 from being contaminated by fragmentsgenerated by the substrates 211, 213 irradiated with plasma.

In addition, although the stacking unit 300 illustrated in the figureincludes the activating apparatuses 326, 336 to activate the substrates211, 213, a different structure from which the activating apparatuses326, 336 of the stacking unit 300 are omitted can also be employed,which structure is made possible by carrying, into the stacking unit300, the substrates 211, 213 that are activated preliminarily using theactivating apparatuses 326, 336 provided separately from the stackingunit 300.

Furthermore, besides a method of exposing substrates 211, 213 to plasma,substrates 211, 213 can be activated by sputter-etching using an inertgas, an ion beam, a fast atomic beam or the like, or a mechanicalprocess such as polishing or the like. If an ion beam or fast atomicbeam is used, the stacking unit 300 can be generated under a reducedpressure. Still furthermore, substrates 211, 213 can also be activatedby ultraviolet light irradiation, an ozone asher or the like.Furthermore, surfaces of substrates 211, 213 may also be activated bychemically purifying them using a liquid or gas etchant, for example.

FIG. 2 is referred to again. Next, the control unit 150 moves the movingstage 332 based on the amount of movement calculated at Step S106, andaligns the substrates 211, 213 as shown in FIG. 12 (Step S108).

FIG. 13 is a schematic view showing how the substrates 211, 213 alignedwith each other at Step S108 appear. Next, as shown in FIG. 14, thecontrol unit 150 raises the moving stage 332 by the Z-direction driveunit 335, bring the aligned substrates 211, 213 into contact with eachother and starts joining of the substrates 211, 213 (Step S109).

As shown in FIG. 15, at the time point at which they come into contactat Step S109, the one flat substrate 211 and the different curvedsubstrate 213 contact at one part. Thereby, as indicated by a regionsurrounded by the dotted line C in the figure, a joint starting point atwhich the substrates 211, 213 are joined partially is formed at theapproximately middles of the substrates 211, 213.

As shown in FIG. 16, after parts of the substrates 211, 213 come intocontact, the control unit 150 discontinues holding of the substrate 211by the substrate holder 221 at the fixation stage 322. The substrate 211that is located on the upper side in the figure and is freed therebyautonomously enlarges its joined region due to its own weight and anintermolecular force of the activated substrates 211, 213 themselves,and eventually is joined entirely. In this manner, a stacked body 230consisting of the substrates 211, 213 is formed in the stacking unit300.

In the stacked body 230, the substrate 213 located on the lower side inthe figure is kept being held by the substrate holder 223 having acurved holding surface 225 throughout the course of stacking at andafter Step S103. Therefore, because the substrate 213 is joined with thesubstrate 211 in a state where it is corrected by the substrate holder223, a magnification difference between the substrates 211, 213 iscorrected.

In the course of enlargement of the contact regions of the substrates211, 213 in the above-mentioned manner, the control unit 150 maypartially or entirely discontinue holding of the substrate 213 by thesubstrate holder 223. In addition, holding of the substrate holder 223by the fixation stage 322 may be discontinued. If holding of thesubstrate 213 is discontinued, in the course of enlargement of thecontact regions, the substrate 213 located on the lower side floatsabove the substrate holder 223 and curves due to a pulling force fromthe substrate 211 located on the upper side. Thereby, because the shapechanges to extend a surface of the substrate 213 located on the lowerside, the difference from the extension amount of a surface of thesubstrate 211 located on the upper side decreases by the formerextension amount.

Accordingly, positional misalignment due to the amounts of deformationthat are different between the two substrates 211, 213 is suppressed.Because a floating amount of the substrate 213 from the substrate holder223 can be adjusted by adjusting the holding force of the substrateholder 223, if a difference occurs between an amount of correctionpreset for a plurality of substrate holders 223 and an actuallynecessary amount of correction, the difference can be compensated for byadjusting the holding force of this substrate holder 223. The differencebetween the amounts of correction is for example calculated by theholder selecting unit 151.

Furthermore, joining of the substrates 211, 213 may be allowed toproceed without releasing the substrate 211 held by the fixation stage322 but by releasing the substrate 213 held by the moving stage 332.Furthermore, the substrates 211, 213 may be joined by bringing thefixation stage 322 and the moving stage 332 close to each other while atthe same time keeping the substrates 211, 213 held by the fixation stage322 and the moving stage 332, individually.

The thus-formed stacked body 230 is carried out of the stacking unit 300by the carrying unit 140 (Step S110), and housed in the substratecassette 130.

FIG. 17 is a schematic view of the holder stocker 400 housing adifferent holder lineup including substrate holders 228, 229. The holderlineup housed in the holder stocker 400 illustrated in the figureincludes the substrate holder 228, 229 having non-spherical holdingsurfaces 225, in addition to substrate holders 221 having flat holdingsurfaces 225 and substrate holders 223 having spherical or paraboloidalholding surfaces 225.

The substrate holder 228 has a holding surface 225 whose middle andregions around the middle are dented. In addition, the substrate holder229 has a holding surface whose curvature at the middle and regionsaround the middle is smaller than other regions. In this manner, byincluding the substrate holder 228 having a holding surface 225 with anon-linearly curved surface whose shape, curvature or the like partiallychanges in a lineup, in addition to the substrate holders 223 having aholding surface 225 with an entirely uniformly linearly curved surface,non-linear components among components of distortion generated to asubstrate 213 can also be corrected. Therefore, for example, ifparticular deformation occurs for reasons related to the structure of asubstrate 213 to be stacked, a manufacturing process thereof, amanufacturing apparatus therefor or the like, a substrate holder 220 tocorrect it can be prepared, and the substrate 213 can be corrected byit.

Furthermore, a linear component and a non-linear component may becorrected at once by using the above-mentioned substrate holders 228,229 that can correct non-linear components by placing them on or under asubstrate holder that can correct linear components such as an isotropicmagnification or correction stages 341, 342, 343, 344, 345, 346mentioned below.

The shapes of holding surfaces 225 formed on the substrate holders 223,228, 229 are not limited to symmetrical shapes like the ones mentionedabove, but may be eccentric shapes, cylindrical shapes or the like. Inaddition, other than a convex shape in which the middle of a holdingsurface 225 protrudes toward a substrate 213, the holding surface 225may have a concave shape with protruding circumference. Furthermore,although in the above-mentioned implementation, a plurality of substrateholders 223 each have a different degree of convexness, instead of this,a plurality of substrate holders 223 each having different curvature maybe used.

Furthermore, other than correction by the shape of a holding surface 225or in addition to correction by the shape of a holding surface 225, theshape of a substrate 213 may be changed by using a plurality ofsubstrate holders that are different from each other in terms of atleast one of the levels of temperatures at holding surfaces 225, thedegrees of surface roughness of holding surfaces 225 of substrateholders relative to substrates 213 and the strengths of holding forcesof holding surfaces 225, as the state of substrate holders.

If a plurality of substrate holders having temperatures that aredifferent from each other are used, substrates 213 held by the substrateholders thermally deform by amounts of deformation corresponding to thetemperatures of the substrate holders. The temperatures of the pluralityof substrate holders may be adjusted using heaters or the likeincorporated into each of the plurality of substrate holders, or each ofthe plurality of substrate holders may be adjusted to an individuallydifferent temperature by a heater provided to the holder stocker 400. Arelationship between substrate holders and amounts of correction or arelationship between temperatures of substrate holders and amounts ofcorrection is preset and stored.

The holder selecting unit 151 selects a substrate holder having atemperature corresponding to an amount of correction that should bemade, based on at least one of: measured amounts of deformation of thetwo substrates 211, 213; a magnification difference between thesubstrates 211, 213 estimated from the deformation amount measurementresult; an amount of positional misalignment between the two substrates211, 213; and amounts of correction of the two substrates 211, 213.

If a plurality of substrate holders having holding surfaces to holdsubstrates with surface roughness that are different from each other areused, a relationship between amounts of correction and surface roughnessor a relationship between amounts of correction and substrate holder arepreset and stored. The surface roughness is for example arithmetic meanroughness (Ra).

In the course of stacking the substrate 213 onto the substrate 211, thereleased substrate 211 expands in the plane direction, and during thatprocess, the held substrate 213 is joined. Therefore, the restorationforce of the released substrate 211 acts on the contractile force of theheld substrate 213. Therefore, depending on the strength of the frictionforce of a substrate holder to act on the substrate 213, an amount ofcontraction due to the contractile force to act on the held substrate213 also differs. Accordingly, according to the friction force to act onthe substrate 213, the contractile force to act on the substrate 213 iscontrolled, and a magnification generated to the substrate 213 at thetime of joining can be changed.

The friction force to act from the holding surface on the substrate 210is not determined by the nature of a surface of the substrate holder 220singly, but it is determined by the sum of the nature of the holdingsurface of the substrate holder 220, the state of a surface of thesubstrate 210 and the weight of the substrate 210 applied onto thesubstrate holder 220. Therefore, if an amount of correction is adjustedby the friction force acting between the substrate 210 and the substrateholder, the friction force that is generated between the substrate 210and the substrate holder 220 is predicted based on the surface roughnessof the substrate 210 held by the substrate holder 220, and a substrateholder 220 to hold the substrate 210 is selected based on it.

The friction forces of the substrate holders 223, 228, 229 to act on thesubstrate 213 can be adjusted not only by surface roughness but also forexample by materials, rigidity or the like of the substrate holders 223,228, 229.

The holder selecting unit 151 selects a substrate holder having aholding surface with surface roughness corresponding to an amount ofcorrection that should be made, based on at least one of: measuredamounts of deformation of the two substrates 211, 213; a magnificationdifference between the substrates 211, 213 estimated from thedeformation amount measurement result; an amount of positionalmisalignment between the two substrates 211, 213; and amounts ofcorrection of the two substrates 211, 213.

In addition, if a plurality of substrate holders having holding surfaceswith holding forces that are different from each other are used, arelationship between amounts of correction and holding forces or arelationship between amounts of correction and substrate holder arepreset and stored. The force of the substrate holder 220 to hold asubstrate 210 can be measured not based on methods of suctionalattraction such as electrostatic suctional attraction or vacuumsuctional attraction but by a suctional attraction force [kPa] to act onthe substrate 210.

In the course of stacking a substrate 213 onto a substrate 211, anamount by which the substrate 213 separates from a substrate holderchanges according to the holding force, due to the intermolecular forcethat the held substrate 213 receives from the substrate 211. When partof the held substrate 213 separates from the substrate holder, thesubstrate 213 is joined with the different substrate 211 while beingdeformed to be convex toward it. Therefore, distortion comparable to achange in distortion including a magnification due to deformationgenerated to the released substrate 211 in the course of joining can begenerated to the held substrate 213. That is, an amount of separation ofthe substrate 213 from the holding surface is controlled according tothe magnitude of the force to hold the substrate 213, and distortiongenerated to the substrate 213 at the time of joining can be changed.

The force of the substrate holder to hold the substrate 213 is set byadjusting voltage if it is held using an electrostatic suctionalattraction force, and is set by adjusting a vacuum force of fluid if itis held using a vacuum suctional attraction force.

The holder selecting unit 151 selects a substrate holder having aholding force corresponding to distortion desired to be generated to thesubstrate 213 in the course of joining, based on at least one of:measured amounts of deformation of the two substrates 211, 213; amagnification difference between the substrates 211, 213 estimated fromthe deformation amount measurement result; an amount of positionalmisalignment between the two substrates 211, 213; and amounts ofcorrection of the two substrates 211, 213.

In this manner, if a plurality of substrate holders that are differentfrom each other in at least one of temperatures of the substrateholders, surface roughness of holding surfaces of the substrate holdersand holding forces are used, amounts of correction to correct positionalmisalignment generated in the course of stacking a substrate 213 onto asubstrate 211 can be changed. Therefore, by using a substrate holderhaving a holding surface in a state corresponding to the amount ofcorrection, the substrate 213 can be corrected by an appropriate amountof correction to reduce positional misalignment between the substrates211, 213.

If temperatures, surface roughness and holding forces of substrateholders are made different, their holding surfaces may be flat or mayform convex shapes like the one shown in FIG. 6. By combining convexshapes and adjustment of temperatures, adjustment of surface roughnessor adjustment of holding forces, if a plurality of substrate holderswith different degrees of convexness are used, the substrate 213 can becorrected by amounts of correction that are different by pitches ofamounts of correction corresponding to individual degrees of convexness.

FIG. 18 is a schematic view of a holder stocker 401 corresponding to adifferent holder lineup. The holder stocker 401 includes a large numberof housing units compared to the holder stocker 400. However, the typesof the substrate holders 221, 223 housed in the holder stocker 401 arenot different from those of the holder stocker 400 shown in FIG. 7.

The holder stocker 401 houses nine types of substrate holders 601, 602,603, 604, 605, 606, 607, 608, 609 with stepwise changing degrees ofconvexness from the substrate holder 601 having a holding surface 225with the largest degree of convexness in the entire holder lineup to thesubstrate holder 609 having a holding surface 225 with the smallestdegree of convexness in the entire holder lineup, the number of eachtype of substrate holder all being one. In addition, the holder stocker401 houses three substrate holders 605 having holding surfaces 225 withan approximately intermediate degree of convexness, and substrateholders 603, 604, 606, 607 having holding surfaces 225 with degrees ofconvexness slightly smaller or larger than that. The number of eachamong the substrate holders 603, 604, 606, 607 is two.

The number of these substrate holders 223 having holding surfaces 225with the same degree of convexness is determined according to thefrequency at which the substrate holders 223 having the degree ofconvexness are selected by the holder selecting unit 151, that is, thenumber of times of selection per unit period. Thereby, wear of eachsubstrate holder 223 through use can be made uniform, and the effectiveuse efficiency of substrate holders 223 can be improved. In this manner,substrate holders 223 housed in the holder stocker 401 may include aplurality of substrate holders having holding surfaces in the samestate.

The lineups of substrate holders 223 housed in the holder stockers 400,401 may be set to have numbers of substrate holders 223 for each kind ofamounts of correction and each amount of correction such that they havedistributions corresponding to the Gaussian distribution in terms of thestate of warping in each lot of the two substrates 211, 213, forexample. In addition, if substrates in lots with warp amounts ofsubstrates 211, 213 that are different from each other are joined or ifsubstrate products with designs different from conventional ones arejoined, the different holder stockers 400, 401 housing different lineupsmay be prepared, and the holder stocker 400, 401 may entirely beretrofitted with entire lineups. Thereby, the work of setting up alineup can be expedited, and the throughput of the stacking apparatus100 can be improved.

Furthermore, the substrate holders 223 housed in the holder stockers400, 401 can be partially or entirely replaced. In addition, a holderlineup consisting of a plurality of substrate holders 223 housed in theholder stocker 400, 401 may be replaced with a different holder stocker400 housing a different holder lineup.

In addition, the holder stockers 400, 401 may be structured to bepartially replaceable or to be able to be additionally provided. In thiscase, substrate holders 223 of high usage frequency are always providedto the stacking apparatus 100, and portions housing substrate holder 223of low usage frequency or characteristic substrate holders 223 havingholding surfaces with shapes other than spherical shapes may beconfigured such that they can be replaced at once. In addition, portionshousing substrate holders 223 of high usage frequency may be configuredsuch that they can be additionally provided or replaced.

Furthermore, at large-scale facilities where a plurality of the stackingapparatuses 100 are installed, each among the plurality of stackingapparatuses 100 may be equipped with a different lineup, and a lineup tobe used for stacking may be changed by selecting a stacking apparatus100 to be used itself, according to the states of shapes of or types ofthe substrates 211, 213 carried into it for stacking.

FIG. 19 is a schematic view of the substrate cassette 120 housingsubstrates 210. As illustrated in the figure, the substrates 210 housedin the substrate cassette 120 form four groups P, Q, R, S, each groupincluding substrates with the approximately same extent of warping.

Thereby, assuming that the substrates 210 housed in the substratecassette 120 are stacked in the order starting from the ones located onthe upper side in the figure, for example, substrate holders 223 whichare in the same state in terms of at least one of curvatures, degrees ofconvexness, temperatures, surface roughness and holding forces can beused successively for each group P, Q, R, S. Therefore, in the stackingunit 300, the number of times of changing substrate holders 223 to beused can be reduced, and the throughput can be shortened.

For the sake of explanation, in FIG. 19, the substrates 210 arephysically sorted, and substrates 210 that require comparable amounts ofcorrection are grouped together. Substrates 210 with comparable amountsof correction mean substrates 210 that can be corrected by the samesingle substrate holder 223, and it means that the differences betweenthe amounts of correction necessary for the substrates 210 and an amountof correction set to the substrate holder 223 are within a toleratedrange. However, a plurality of substrates 210 may be housed in thesubstrate cassette 120 without being grouped. In this case, based oninformation to identify individual ones of the substrates 210 andinformation about amounts of correction necessary for the substrates,the carrying unit 140 is controlled by the control unit 150 of thestacking apparatus 100, and the order of carrying out the plurality ofsubstrates 210 may be changed such that substrate holders 223 in thecomparable state in terms of at least one of curvatures, degrees ofconvexness, temperatures, surface roughness and holding forces are usedsuccessively.

Furthermore, the control unit 150 may select, from a plurality ofsubstrates 210 housed in the substrate cassette 120, a substrate 210suited for the state of a holding surface of a substrate holder 220currently being used in the stacking apparatus 100, and may prioritizethe substrate 210 for a stacking process. In this case, if the holderselecting unit 151 selects one substrate holder 223 to be used incorrection at Step S102, the substrate selecting unit 152 may select asubstrate 213 that can be corrected by the substrate holder 223, andstack the substrate 213 in the next stacking process. Thereby, thethroughput of the stacking apparatus 100 can be improved byconsecutively using one substrate holder 220 and saving time forreplacement of substrate holders 220.

Information to identify individual ones of the substrates 210 may begiven to the individual substrates 210 as bar codes that are readable bythe control unit 150 or the like. In addition, information to identifyindividual ones of the substrates 210 may be used as information toidentify the housing positions of the individual substrates 210 in thesubstrate cassette 120.

Information used about amounts of correction of substrates may be theabove-mentioned shape-related information of the substrates 210. Amountsof correction applied to the individual substrates 210 may be predictedor calculated from shape-related information about individual ones amongthe substrates 210.

FIG. 20 is a schematic plan view of a different stacking apparatus 101.Except for portions explained next, the stacking apparatus 101 has thesame structure as that of the stacking apparatus 100 shown in FIG. 1.Therefore, common elements between the stacking apparatus 100 and thestacking apparatus 101 are given the same reference numerals, and thesame explanations are omitted.

The stacking apparatus 101 has a structure different from the stackingunit 300 in that it includes a waiting unit 160 provided adjacent to aprealigner 501. The waiting unit 160 can keep any of substrate holders223 used for correction of a substrate 213 waiting, placing it veryclose to the prealigner 501.

Here, the substrate holder 223 placed in the waiting unit 160 may be asubstrate holder 223 with high usage frequency. In addition, thesubstrate holder 223 placed in the waiting unit 160 may be a substrateholder 223 used at a next stacking process following an on-goingstacking process. Thereby, a length of time required for changing asubstrate holder 223 to use can be shortened, and the throughput of thestacking apparatus 101 can be shortened.

FIG. 21 is a schematic perspective view of the stage apparatus 340. Thisstage apparatus 340 includes a single fixation stage 322, and aplurality of correction stages 341, 342, 343, 344, 345, 346. Each of thecorrection stages 341, 342, 343, 344, 345, 346 and fixation stage 322 isa different exemplary holding member, and has a holding mechanisms tosuctionally attract and hold a substrate 210.

The plurality of correction stages 341, 342, 343, 344, 345, 346 aredisposed along a common circle on a common turntable 347. The turntable347 rotates about its vertical axis of rotation. In addition, each ofthe plurality of correction stages 341, 342, 343, 344, 345, 346 has thefunction of rising and lowering in a direction parallel with the axis ofrotation of the turntable 347. The plurality of correction stages 341,342, 343, 344, 345, 346 have holding surfaces in states that aredifferent from each other.

The fixation stage 322 on which the substrate 211 is held is fixed toface downward in the figure from the frame 348 lying across theturntable 347. Thereby, rotating the turntable 347 can make any of thecorrection stages 341, 342, 343, 344, 345, 346 on which the substrate213 is held face the fixation stage 322. The above-mentioned pluralityof correction stages 341, 342, 343, 344, 345, 346 and a plurality ofsubstrate holders 223 having different degrees of convexness or the likemay be used in combination to thereby be able to more finely adjust anamount of correction.

FIG. 22 is a schematic view of the stage apparatus 340 in which thestage apparatus is unfolded for explaining the function of it. Thefixation stage 322 holds a substrate along its flat holding surface. Incontrast, in the example illustrated in the figure, the plurality ofcorrection stages 341, 342, 343, 344, 345, 346 have holding surfaceswith degrees of convexness that are different from each other, and holdsubstrates along their holding surfaces.

In such a stage apparatus 340, any of the plurality of correction stages341, 342, 343, 344, 345, 346 is selected based on at least one of:measured amounts of deformation of the two substrates 211, 213; amagnification difference between the substrates 211, 213 estimated fromthe deformation amount measurement result; an amount of positionalmisalignment between the two substrates 211, 213; and amounts ofcorrection of the two substrates 211, 213. The selected correction stageis caused to hold the substrate 210 directly to thereby be able tocorrect the substrate 210 by a different amount of correction withoutusing the substrate holder 223. Therefore, using the stage apparatus340, the stacking unit 300 to stack a substrate 210 while at the timecorrecting it can be formed without using a substrate holder 220.

While the embodiments of the present invention have been described, thetechnical scope of the invention is not limited to the above describedembodiments. It is apparent to persons skilled in the art that variousalterations and improvements can be added to the above-describedembodiments. It is also apparent from the scope of the claims that theembodiments added with such alterations or improvements can be includedin the technical scope of the invention.

The operations, procedures, steps, and stages of each process performedby an apparatus, system, program, and method shown in the claims,embodiments, or diagrams can be performed in any order as long as theorder is not indicated by “prior to,” “before,” or the like and as longas the output from a previous process is not used in a later process.Even if the process flow is described using phrases such as “first” or“next” in the claims, embodiments, or diagrams, it does not necessarilymean that the process must be performed in this order.

What is claimed is:
 1. A stacking apparatus that stacks a firstsubstrate and a second substrate, the stacking apparatus comprising: aplurality of holding members that hold the first substrate, wherein theplurality of holding members correct positional misalignment of thefirst substrate relative to the second substrate by preset amounts ofcorrection, and the plurality of holding members include holding membershaving the amounts of correction that are different from each other. 2.The stacking apparatus according to claim 1, comprising a holding memberselecting unit that selects, from the plurality of holding members, aholding member to hold the first substrate based on information aboutthe first substrate and the second substrate.
 3. The stacking apparatusaccording to claim 2, further comprising a substrate selecting unit thatselects a different substrate to be corrected by being held by theholding member selected by the holding member selecting unit, whereinthe different substrate selected by the substrate selecting unit is heldby the holding member selected by the holding member selecting unit, andthe different substrate is stacked successively to stacking of the firstsubstrate.
 4. The stacking apparatus according to claim 2, furthercomprising a carrying unit that carries the holding member selected bythe holding member selecting unit from a position where the holdingmember is housed to a position where the first substrate is held.
 5. Thestacking apparatus according to claim 4, wherein the information aboutthe first substrate and the second substrate includes shape-relatedinformation of at least either the first substrate or the secondsubstrate.
 6. The stacking apparatus according to claim 5, wherein theshape-related information includes information about warping or bendingof at least either the first substrate or the second substrate.
 7. Thestacking apparatus according to claim 5, wherein the shape-relatedinformation includes information about distortion, in a plane direction,of at least either the first substrate or the second substrate.
 8. Thestacking apparatus according to claim 5, wherein the shape-relatedinformation includes a difference in a shape of the first substrate froma predetermined shape.
 9. The stacking apparatus according to claim 5,wherein the shape-related information includes a difference in a shapeof the first substrate from a shape of the second substrate.
 10. Thestacking apparatus according to claim 4, wherein the information aboutthe first substrate and the second substrate includes information aboutpositional misalignment between the first substrate and the secondsubstrate, and the holding member selecting unit selects the holdingmember based on the information about the positional misalignment. 11.The stacking apparatus according to claim 10, comprising a calculatingunit that calculates an amount of correction that makes an amount ofpositional misalignment between the first substrate and the secondsubstrate equal to or smaller than a threshold, wherein the holdingmember selecting unit selects the holding member corresponding to theamount of correction calculated by the calculating unit.
 12. Thestacking apparatus according to claim 11, comprising a control unit thatcontrols a holding force of the plurality of holding members, whereinthe calculating unit calculates a difference between an amount ofcorrection set to the holding member selected by the holding memberselecting unit and a calculated amount of correction, and the controlunit controls the holding force based on the calculated difference. 13.The stacking apparatus according to claim 1, wherein the plurality ofholding members include holding members that each deform the firstsubstrate by a preset amount of deformation and have amounts ofdeformation that are different from each other among the holdingmembers.
 14. The stacking apparatus according to claim 1, wherein theplurality of holding members include holding members that each have aholding surface to hold the first substrate, and shapes of the holdingsurfaces are different from each other among the holding members. 15.The stacking apparatus according to claim 14, wherein the plurality ofholding members include holding members having degrees of convexness andcurvatures of the holding surfaces, at least either the degrees ofconvexness or curvatures being different from each other among theholding members.
 16. The stacking apparatus according to claim 1,wherein the plurality of holding members include holding members thateach have a holding surface to hold the first substrate, and surfaceroughness of the holding surfaces to the first substrate is differentfrom each other among the holding members.
 17. The stacking apparatusaccording to claim 1, wherein the plurality of holding members includeholding members that each have a holding surface to hold the firstsubstrate, and temperatures of the holding surfaces are different fromeach other among the holding members.
 18. The stacking apparatusaccording to claim 1, wherein the plurality of holding members includeholding members having holding surfaces to hold the first substrate, andforces to hold the first substrate on the holding surfaces are differentfrom each other among the plurality of holding members.
 19. The stackingapparatus according to claim 1, wherein the plurality of holding membersinclude substrate holders that are carried together with the firstsubstrate being held.
 20. The stacking apparatus according to claim 1,wherein any of the plurality of holding members includes a stage to holdthe first substrate having been carried in.
 21. The stacking apparatusaccording to claim 1, wherein the plurality of holding members furtherinclude holding members to correct the positional misalignment by thesame amount of correction.
 22. A stacking apparatus that stacks a firstsubstrate and a second substrate, the stacking apparatus comprising: aplurality of holding members that holds the first substrate, wherein theplurality of holding members each have a different shape.
 23. A stackingapparatus that stacks a first substrate and a second substrate, thestacking apparatus comprising: a plurality of holding members that eachhave a holding surface to hold the first substrate, wherein a holdingsurface of each of the plurality of holding members has a differentstate.
 24. The stacking apparatus according to claim 23, wherein thestate is at least one of a shape of the holding surface, a level oftemperature, a degree of surface roughness and a strength of holdingforce.
 25. A stacking method of stacking a first substrate and a secondsubstrate, the stacking method comprising: preparing a plurality ofholding members that holds the first substrate and corrects positionalmisalignment of the first substrate relative to the second substrate bypreset amounts of correction, the plurality of holding members includingholding members to correct the first substrate by amounts of correctionthat are different from each other, and causing any of the plurality ofholding members to hold the first substrate based on information aboutthe first substrate and the second substrate.
 26. The stacking methodaccording to claim 25, further comprising: selecting a plurality ofsubstrates to be corrected by one holding member of the plurality ofholding members by an amount of correction set to the one holdingmember; and stacking the selected plurality of substrates successivelyusing the one holding member repeatedly.